Friday, April 29, 2011

When Normal is Abnormal

In the last week of my Introduction to Clinical Medicine course, we had a middle aged women patient with hypothyroidism. She had a bought with Grave's disease and ended up with radioactive iodine therapy which, though it cured her hyperthyroidism, left her with hypothyroidism. She was later put on levothyroxine but ever few years they needed to increase the dose. I remember asking if this was typical to our clinical professor that day, Dr. R, and he said that this is quite common with hypothyroid patients.


My friend B also has hypothyroidism. B also developed hypothyroidism as a result of radiation, but this was for her Hodgkin's Lymphoma, which she successfully beat. B initially went undiagnosed until her Oncologist, and the best Doc she's ever had, noticed her sweating too much when she came in once, and immediately ordered a TSH test. Since then she was placed on 50ug of Levothyroxine and her TSH was typically around 1.1 (reference range 0.4 - 5, though there is some debate about this).

Sir Charles Robert Harington, discovered the structure and synthesis of levothyroxine

Over the past year or so, B started to notice her hair falling out. At first she thought it was due to two surgeries she had within a few months of each other (both for unrelated conditions). Her previous Endocrinologist took a job in another city and so she saw a new one at a prestigious university last June. After looking at her TSH (2.2) and examining her rather quickly, she told her "your hair is not going to all fall out" and rather rudely dismissed her concerns.
Dismayed by this for a while, B continued to watch her hair fall out for the next several months and then started to get some painful acne. After this she made an appointment with a Dermatologist in November. Her PCP signed off on the referral, though he didn't have much insight into her hair loss either. The Dermatologist examined her and drew some blood. Before she got any results back she prescribed spironolactone, presumably for its anti-androgenic effects to counter the acne and hair loss. She ran her own tests and noticed she had a slightly elevated aldosterone, called B and told her to take the spironolactone.
The spiro at first stopped the hair loss but didn't induce much regrowth. After a month on it without any complaints, the Derm doubled the dose to induce regrowth. Within a few weeks B started to notice some strange side effects, though not entirely uncommon. She stuck through this (she is a very compliant patient) but then started to just get plain lethargic over the end of winter and into spring. She also stopped working out and couldn't seem to keep her apartment organized. B thought perhaps it was the long, cold winter but then she started to get salt cravings and gain some weight. Again, possibly spiro side effects, at least the salt craving.
Since spiro is a potassium sparing diuretic, one must be careful about potassium intake. One day in March, B ate a bit too much broccoli and appeared to get symptoms of hyperkalemia. It could also have been just bad broc, but after that she was scared off eating anything with a lot of potassium - cutting out some of the fruit staples of her diet such as bananas and juices. After this, she started to feel insatiable hunger and, as a cancer survivor, started to get paranoid about the constellation of symptoms of tired, hunger and generally feeling ill.
Just this past week she had her yearly check up with her Oncologist. After reporting how she felt to the interns and doing some blood work, they came to a rather obvious conclusion: B needed to increase her dose of levothyroxine. It turns out that at this appointment, her TSH had risen to 3.3, while still in the "normal reference range", her oncologist knew her history and that B's typical range for proper thyroid treatment was a TSH of around 1. She prescribed a dose of 75ug and explained that her hair loss, weight gain, and lethargy were all likely due to the hypothyroidism.


Looking back on this, there are a few interesting lessons. First, the reference range does not always tell the whole story. References ranges are in fact based on the population mean for a lab value, +/- 2 standard deviations. This helps us see pathological outliers, but it doesn't always tell the most accurate story for an individual. It reminds me of another story where a fellow med student, and former nurse, said someone could have a blood sugar of 40 be not outrageously low (though we're taught <60 is low) because he could just be someone who has low sugar. While I have not had enough clinical experience to appreciate this, it seems to make sense and was certainly analogously true for B.
Also, I know my own personal clinical judgement got warped when trying to help B figure out what was wrong. Makes me wonder how much physicians can really get emotionally vested in their patients before we start to see what we want rather than what is really taking place.
However, the most disturbing aspect of this whole endeavor was the fact that 3 separate, board-certified physicians completely missed what was going on. Not only were her symptoms dismissed (endocrinologist), completely missed (primary care doc) but she was also misdiagnosed and given an unnecessary treatment (dermatologist). A year of distressingly losing hair and the psychological consequences of that, gaining weight, rising blood lipids and also some inflammation on top of it all, could have been avoided if someone had just put together her symptoms with her #1 chronic condition and what is "normal reference range" for her, individually.
It raises many questions about the coordination of care, the role of medical records, and even the attentiveness (perhaps overworked, perhaps not) of the physicians in our US healthcare system. I just wonder how typical such cases truly are... and will certainly do my best to keep this in mind on my clinical rotations later this year.


Spice Island Queen said...

great post and food for thought. thanks JP. best of luck finishing your time on the island. i do miss it..

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